about 75% of hydrogen
22% helium
traces of most other elements including oxygen, neon, carbon and nitrogen
All the above
D. All the above
appears to increase
appears to decrease
does not change at all
first increases then decreases
their heat contents
their masses
their temperatures
whether they are in solid, liquid or gaseous state
to keep it away from the hot compressor which is near the bottom
because of convenience
so that it can cool the whole interior by setting up convection currents
to prevent too much cooling
so that they may reflect thermal radiation from outside and minimise such radiation from them
so that they may absorb all radiation from outside
to make them attractive to look at
because they take high polish
electrons
neutrons
neutrons and electrons
electrons, neutrons and other particles
mininuclear reactor
a dynamo
a thermopile
solar cells
10000 to 20000 Hz
50 to 15000 Hz
20 to 20000 Hz
15 to 50000 Hz
lead
zinc
carbon
tin
Albert Einstein
Enrico Fermi
HJ Bhabha
Sir Isaac Newton
Joule
Newton
Joule/Sec
Erg/Sec
can focus very rapidly as pictures change
is quicker than the brain
can see two images separated only if the interval' between seeing them is more than' one-tenth of a second
can shut out some of the light
Uranium that is very pure
Uranium in which the concentration of the isotope U-238 is more than in the naturally occuring uranium
Uranium in which the concentration of the isotope U-235 is more than in the naturally occuring uranium
None of the above
the centripetal force
the centrifugal force
the frictional force
All the above
330 m
33 m
16.5 m
165 m
look like falling stars
are really pieces of rock or metal
burn up as they shoot through the air
All the above
Proxima Centauri
Sirius
Aldebaran
Vega
is found by measuring the slanting height of the mercury column
is given by the vertical height
cannot be measured with it
u) can be measured by both the methods described above
remain in the car
get out of the car and lie flat in the ground
abandon the car and take shelter under a nearby tree
touch the nearest electric pole
Bernoulli's principle
Magnetic properties of the ship's material
Newton's third law of motion
Earth's gravitational force
umbra
penumbra
image
black portion of light
the atoms and molecules lose their identity
nucleus is split into fragments
the nuclear reaction between two light atomic nuclei results in the formation of a heavier nucleus with release of a large quantity of nuclear energy in the process
absorption of neutron by a nucleus
fish are cold-blooded animals
ice is a bad conductor of heat
there will always be water just beneath the ice level
they can adapt themselves to live in ice
first
second
third
fourth
temperature of air
intensity of light
density of a liquid
relative humidity of the atmosphere
Sir Isaac Newton
Columbus
Archimedes
Thomas Alva Edison
the electrical attraction between the negatively charged electron and the positively charged porton
the high speed of the electron
the low speed of the electron
gravity
the same direction as the motion
the opposite direction of the motion
all the directions
upward direction
Tin
Lead
Nickel
An alloy of tin and lead
ultraviolet rays
gamma rays
radio waves
infrared waves
40 years
50 years
76 years
80 years